diff --git a/xCAT/postscripts/xcatserver b/xCAT/postscripts/xcatserver
index 8b698ae8a..b4886e412 100755
--- a/xCAT/postscripts/xcatserver
+++ b/xCAT/postscripts/xcatserver
@@ -31,7 +31,7 @@ USEOPENSSLFORXCAT=1
 export USEOPENSSLFORXCAT
 # are we using xcat flow control
 useflowcontrol=0
-if [ $USEFLOWCONTROL = "YES" ] || [ $USEFLOWCONTROL = "yes" ] || [ $USEFLOWCONTROL = "1" ]; then
+if [ "$USEFLOWCONTROL" = "YES" ] || [ "$USEFLOWCONTROL" = "yes" ] || [ "$USEFLOWCONTROL" = "1" ]; then
   useflowcontrol=1
 fi